A conventional rapid insertion-type AC mains power plug is depicted in FIG. 1, wherein there are prongs (11) at the front end and a pair of insertion holes at the rear end (12) that provides for the insertion of another AC mains power plug (2) to permit the extension of the electrical current source. However, since the rear end (12) of the aforesaid conventional AC mains power plug is comprised of a fiat surface, when another AC mains power plug (2) is inserted, the AC mains power plug (2) is easily dislodged by the impact of an external force during usage such that angle of insertion is no longer perpendicular or even result in complete removal due to impractical structure of the aforementioned conventional AC mains power plug.
The primary objective of the invention herein is to overcome the disadvantages of conventional AC mains power plug products and to provide a stable safe design, the innovations and effectiveness of which are elaborated in the attached drawings and derailed description of the invention herein.